<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

 <h1>显示页面的内容</h1>
  <button>ajax</button>
</body>
</html>
<script src="../js/jquery-3.1.0.min.js"></script>
<script>

    $("button").click(function(){

        $.ajax({
            url:"../book/showAll",
            type:"get",
            success:function(data){
                console.log(data);
            }
        });

    });

</script>